Feasibility and Accuracy of Fast MRI Versus CT for Traumatic Brain Injury in Young Children

Head computed tomography in suspected physical abuse: time to rethink?

BACKGROUND

National guidance recommends CT-head for all children <1 year old with suspected physical abuse, and to be considered for those <2 years old to exclude abusive head trauma.

OBJECTIVES

To investigate whether this guidance is followed, and the associations between clinical presentation and CT findings, to determine whether guidance could be refined.

MATERIALS AND METHODS

A retrospective case note review of all children <2 years old who underwent medical assessment for suspected abuse (2009-2017). Outcome measures were frequency of CT-head, and diagnostic yield of intracranial injury, skull fracture or both.

RESULTS

CT-head was undertaken in 60.3% (152/252) of children <12 months old and 7.8% (13/167) of those aged 12-24 months. The diagnostic yield in children who had a CT-head was 27.1% in children <6 months old, 14.3% in those 6-12 months old (p=0.07) and 42.6% (6/13) in those 12-24 months old. For those with head swelling or neurological impairment, it was 84.2% (32/38). In children <12 months old without these clinical features, the estimated prevalence of occult head injury was 6.1% (7/115). The strongest predictors of an abnormal CT-head were swelling to the head (OR 46.7), neurological impairment (OR 20.6) and a low haemoglobin (OR 11.8).

CONCLUSION

All children <2 years of age with suspected physical abuse and neurological impairment or head swelling should undergo CT-head. Where the technical skills and the requisite expertise to interpret MRI exist, an MRI scan may be the optimal first-line neuroimaging investigation in infants who are neurologically stable with injuries unrelated to the head to minimise cranial radiation exposure.

Utility of a pediatric fast magnetic resonance imaging protocol as surveillance scanning for traumatic brain injury

OBJECTIVE

Traumatic brain injury (TBI) is a prevalent pediatric pathology in the modern emergency department. Computed tomography (CT) is utilized for detection of TBI and can result in cumulatively high radiation exposure. Recently, a fast brain magnetic resonance imaging (fbMRI) protocol has been employed for rapid imaging of hydrocephalus in pediatric patients. The authors investigate the utility of a modified trauma-focused fbMRI (t-fbMRI) protocol as an alternative to surveillance CT in the setting of acute TBI in pediatric patients, thus reducing radiation exposure while improving diagnostic yield.

METHODS

A retrospective review was performed at the authors' institution for all pediatric patients who had undergone t-fbMRI within 72 hours of an initial CT scan, using a 1.5- or 3-T MR scanner for trauma indications. Forty patients met the study inclusion criteria. The authors performed a comparison of findings on the reads of CT and fbMRI, and a board-certified neuroradiologist conducted an independent review of both modalities.

RESULTS

T-fbMRI outperformed CT in specificity, sensitivity, and negative predictive value for all injury pathologies measured, except for skull fractures. T-fbMRI demonstrated a sensitivity of 100% in the detection of extraaxial bleed, intraventricular hemorrhage, and subarachnoid hemorrhage and had a sensitivity of 78% or greater for epidural hematoma, subdural hematoma, and intraparenchymal hemorrhage. T-fbMRI yielded a specificity of 100% for all types of intracranial hemorrhages, with a corresponding negative predictive value that exceeded that for CT.

CONCLUSIONS

In pediatric populations, the t-fbMRI protocol provides a valid alternative to CT in the surveillance of TBI and intracranial hemorrhage. Although not as sensitive in the detection of isolated skull fractures, t-fbMRI can be used to monitor pathologies implicated in TBI patients while minimizing radiation exposure from traditional surveillance imaging.

Trends and variation in repeat neuroimaging for children with traumatic intracranial hemorrhage

OBJECTIVES

We aimed to determine trends and institutional variation in repeat neuroimaging in children with traumatic intracranial hemorrhage and to identify factors associated with neuroimaging modality (subsequent magnetic resonance imaging [MRI] vs computed tomography [CT]).

METHODS

We conducted a retrospective cross-sectional study of 35 hospitals in the Pediatric Health Information System database. We included children <18 years of age hospitalized from 2010-2019 with intracranial hemorrhage and who underwent a brain CT. We calculated repeat neuroimaging rates by modality and used regression analyses to examine temporal trends. We used hierarchical logistic regression to identify factors associated with subsequent MRI versus repeat CT, controlling for hospital.

RESULTS

We identified 12,714 children with intracranial hemorrhage, of which 5072 with repeat neuroimaging were studied. Of the 5072 children with repeat neuroimaging, repeat CT was performed in 67.6% (n = 3429) and subsequent MRI in 32.4% (n = 1643). Overall repeat neuroimaging with either a CT or MRI remained similar from 2010-2019 (P = 0.431); however, repeat CT scans significantly decreased (P = 0.001); whereas, MRIs significantly increased (P < 0.001). Repeat neuroimaging by hospital ranged from 20%-80%. After controlling for institution, subsequent MRI was more likely to be used in younger children and children who did not receive hyperosmotic agents, neurosurgical interventions, or intensive care unit admission (all P-values <0.001).

CONCLUSIONS

We found that repeat neuroimaging rates for children with intracranial hemorrhage vary substantially by institution. We also found that although MRI was increasingly used to re-image these children, overall repeat neuroimaging rates (CT or MRI) have not decreased over the past decade. Future work to implement optimal utilization of neuroimaging in these children is needed.

The Diagnostic Efficacy of MRI in the Evaluation of the Enlarged Vestibular Aqueduct in Children with Hearing Loss

Objective

The aim of our study is to evaluate the diagnostic effectiveness of magnetic resonance imaging (MRI) compared to computed tomography (CT) in the detection of enlarged vestibular aqueduct (EVA) in childhood.

Methods

One hundred twenty-three children who underwent temporal bone CT and MRI examinations for hearing loss between 2013 and 2020 were evaluated retrospectively. All CT and MRI images were examined by two pediatric radiologists, according to the Valvassori and Cincinnati criteria for EVA. Imaging findings on CT and MRI of the vestibular aqueduct were recorded. Two pediatric radiologists performed the measurements for EVA on CT and MRI. In addition, an otolaryngologist performed the measurements independently. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRI compared to CT were calculated to detect EVA. The difference between the measurements on CT and MRI was investigated. The inter-observer agreement was evaluated for measurements.

Results

The mean age of 123 children (65 boys and 58 girls) was 50.18±50.40 months. Two hundred forty-six ears were evaluated in 123 children. On CT images, EVA was present in 28 (11.3%) of 246 ears according to Cincinnati criteria and 27 (10.9%) of 246 ears according to Valvassori criteria, respectively. While sensitivity, specificity, PPD, and NPD rates of MRI were 100%, 99%, 92.8%, and 100%, respectively, for Cincinnati criteria, for Valvassori criteria, they were 100%, 97.3%, 77.7%, and 100%, respectively. According to the visual evaluation performed without using measurement, the enlarged appearance of the vestibular aqueduct was significant for the diagnosis of EVA (p<0.001), while the absence of this appearance was significant for the exclusion of EVA (p<0.001). There was no significant difference between the measurements on CT and MRI. There was a perfect correlation between the observers for measurements.

Conclusion

MRI can be used as an initial imaging technique in children with suspicion of EVA to reduce radiation exposure.

Addressing Key Clinical Care and Clinical Research Needs in Severe Pediatric Traumatic Brain Injury: Perspectives From a Focused International Conference

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in children and adolescents. Survivors of severe TBI are more prone to functional deficits, resulting in poorer school performance, poor health-related quality of life (HRQoL), and increased risk of mental health problems. Critical gaps in knowledge of pathophysiological differences between children and adults concerning TBI outcomes, the paucity of pediatric trials and prognostic models and the uncertain extrapolation of adult data to pediatrics pose significant challenges and demand global efforts. Here, we explore the clinical and research unmet needs focusing on severe pediatric TBI to identify best practices in pathways of care and optimize both inpatient and outpatient management of children following TBI.

Trends of computed tomography use among children in Finland

Objectives

CT is an essential diagnostic tool in health care. However, CT delivers relatively high levels of radiation which has been associated with an increased risk of childhood cancer. To address this, we evaluated patterns and time trends of CT use among children in Finland during the period in which changes in pediatric CT imaging practices were reported in several countries.

Methods

Data on CTs performed on children younger than 15 years were obtained from Finland’s largest eight hospitals. CT data included the period 1996–2010 with an estimated coverage of more than 80 % of pediatric CT imaging in Finland. Joinpoint regression was used for trends analysis. CT radiation doses were estimated based on a Finnish dosimetry survey.

Results

A total of 48,807 pediatric CTs were performed in 1996–2010. More boys (55.5 %) were scanned than girls (42.8 %). CT numbers increased up to 2002, then decreased significantly (-6.9 % per year, 95 % CI: -10.4 to -3.2) towards 2005 and to a lesser extent thereafter, particularly among younger children. All CT types decreased in recent years, except for chest, spine, and extremities. The frequency of head CTs related to the diagnoses of intracranial injury, migraine and headache decreased towards the end of the study period. The estimated annual average effective dose from the three most common CT examinations was 0.004 mSv per child in the population.

Conclusions

The frequency of pediatric CTs in Finland started to decrease after 2002. Apart from chest and orthopedic CTs, the utilization of pediatric CT imaging declined in recent years, most likely explained by improved awareness of medical radiation risks and reliance on alternative modalities such as MRI and ultrasound.

Magnetic Resonance Imaging of the Brain in the Pediatric Emergency Department

Emergent imaging of the brain is often required to diagnose and manage serious and life-threatening conditions for children presenting to the emergency department. In an effort to reduce children's exposure to ionizing radiation, the use of magnetic resonance imaging (MRI) as an alternative to computed tomography (CT) is increasing. In some conditions, an urgent MRI rather than CT is critical for making management decisions. The purpose of this review is to highlight 3 emergency medical conditions-acute stroke, traumatic brain injury, and hydrocephalus-in which timely MRI of the brain is required for diagnosis and management. Another aim will be to guide providers in determining when and what limited MRI sequences of the brain can be used in lieu of CT in these emergency medical conditions.

Emergency department implementation of abbreviated magnetic resonance imaging for pediatric traumatic brain injury

Pediatric head injury is a common presenting complaint in the emergency department (ED), often requiring neuroimaging or ED observation for diagnosis. However, the traditional diagnostic neuroimaging modality, head computed tomography (CT), is associated with radiation exposure while prolonged ED observation impacts patient flow and resource utilization. Recent scientific literature supports abbreviated, or focused and shorter, brain magnetic resonance imaging (MRI) as a feasible and accurate diagnostic alternative to CT for traumatic brain injury. However, this is a relatively new application and its use is not widespread. The aims of this review are to describe the science and applications of abbreviated brain MRI and report a model protocol's development and ED implementation in the evaluation of children with head injury for replication in other institutions.

Can QuickBrain MRI replace CT as first-line imaging for select pediatric head trauma?

OBJECTIVE

The current standard of care for initial neuroimaging in injured pediatric patients suspected of having traumatic brain injury is computed tomography (CT) that carries risks associated with radiation exposure. The primary objective of this trial was to evaluate the ability of a QuickBrain MRI (qbMRI) protocol to detect clinically important traumatic brain injuries in the emergency department (ED). The secondary objective of this trial was to compare qbMRI to CT in identifying radiographic traumatic brain injury.

METHODS

This was a prospective study of trauma patients less than 15 years of age with suspected traumatic brain injury at a level 1 pediatric trauma center in Portland, Oregon between August 2017 and March 2019. All patients in whom a head CT was deemed clinically necessary were approached for enrollment to also obtain a qbMRI in the acute setting. Clinically important traumatic brain injury was defined as the need for neurological surgery procedure, intubation, pediatric intensive care unit stay greater than 24 hours, a total hospital length of stay greater than 48 hours, or death.

RESULTS

A total of 73 patients underwent both CT and qbMRI. The median age was 4 years (interquartile range [IQR] = 1-10 years). Twenty-two patients (30%) of patients had a clinically important traumatic brain injury, and of those, there were 2 deaths (9.1%). QbMRI acquisition time had a median of 4 minutes and 52 seconds (IQR = 3 minutes 49 seconds-5 minutes 47 seconds). QbMRI had sensitivity for detecting clinically important traumatic brain injury of 95% (95% confidence interval [CI] = 77%-99%). For any radiographic injury, qbMRI had a sensitivity of 89% (95% CI = 78%-94%).

CONCLUSION

Our results suggest that qbMRI has good sensitivity to detect clinically important traumatic brain injuries. Further multi-institutional, prospective trials are warranted to either support or refute these findings.

Simultaneous time of flight-MRA and T2* imaging for cerebrovascular MRI

PURPOSE

3D multi-echo gradient-recalled echo (ME-GRE) can simultaneously generate time-of-flight magnetic resonance angiography (pTOF) in addition to T2*-based susceptibility-weighted images (SWI). We assessed the clinical performance of pTOF generated from a 3D ME-GRE acquisition compared with conventional TOF-MRA (cTOF).

METHODS

Eighty consecutive children were retrospectively identified who obtained 3D ME-GRE alongside cTOF. Two blinded readers independently assessed pTOF derived from 3D ME-GRE and compared them with cTOF. A 5-point Likert scale was used to rank lesion conspicuity and to assess for diagnostic confidence.

RESULTS

Across 80 pediatric neurovascular pathologies, a similar number of lesions were reported on pTOF and cTOF (43-40%, respectively, p > 0.05). Rating of lesion conspicuity was higher with cTOF (4.5 ± 1.0) as compared with pTOF (4.0 ± 0.7), but this was not significantly different (p = 0.06). Diagnostic confidence was rated higher with cTOF (4.8 ± 0.5) than that of pTOF (3.7 ± 0.6; p < 0.001). Overall, the inter-rater agreement between two readers for lesion count on pTOF was classified as almost perfect (κ = 0.98, 96% CI 0.8-1.0).

CONCLUSIONS

In this study, TOF-MRA simultaneously generated in addition to SWI from 3D MR-GRE can serve as a diagnostic adjunct, particularly for proximal vessel disease and when conventional TOF-MRA images are absent.

[Fast MRI sequences for clarification of acute neurological symptoms]

CLINICAL/METHODICAL ISSUE

Neurological symptoms account for approximately 30% of emergency room (ER) visits. Clinical outcome often relies on a timely diagnosis and treatment initiation. Clinical imaging requirements are fast availability and high diagnostic value.

STANDARD RADIOLOGICAL METHODS

Availability and quality of magnetic resonance imaging (MRI) in emergency rooms outside of core hours are limited compared to computed tomography (CT). Common reasons are infrastructural accessibility (hospitals using outpatient radiology centers), a lack of experienced and qualified staff and high patient compliance requirements. However, in a neurological emergency setting, MRI may show relevant advantages over CT in certain areas, such as diagnosis of stroke.

METHODOLOGICAL INNOVATIONS

Advances in MRI technology have led to shorter exam times and robust motion reduction strategies. Common fast sequences and time reduction techniques for imaging of neurological emergencies are presented in this article.

ACHIEVEMENTS

Recommendations for specific sequences or techniques depend on the institute's MRI hardware and software components. If available, parallel imaging is highly recommended for imaging of neurological emergencies.

PRACTICAL RECOMMENDATIONS

Imaging of neurological emergencies requires fast, significant and motion insensitive standard acquisitions. Additional sequences should be acquired dependent on clinical and standard protocol imaging findings. An MRI emergency protocol is introduced for the most common neurologic emergencies including recommendations for fast MRI sequences and techniques for imaging time reduction.

Trends in Use of Advanced Imaging in Pediatric Emergency Departments, 2009-2018

Importance

There is increased awareness of radiation risks from computed tomography (CT) in pediatric patients. In emergency departments (EDs), evidence-based guidelines, improvements in imaging technology, and availability of nonradiating modalities have potentially reduced CT use.

Objective

To evaluate changes over time and hospital variation in advanced imaging use.

Design, Setting, and Participants

This cross-sectional study assessed 26 082 062 ED visits by children younger than 18 years from the Pediatric Health Information System administrative database from January 1, 2009, through December 31, 2018.

Exposures

Imaging.

Main Outcomes and Measures

The primary outcome was the change in CT, ultrasonography, and magnetic resonance imaging (MRI) rates from January 1, 2009, to December 31, 2018. Imaging for specific diagnoses was examined using all patient-refined diagnosis related groups. Secondary outcomes were hospital admission and 3-day ED revisit rates and ED length of stay.

Results

There were a total of 26 082 062 visits by 9 868 406 children (mean [SD] age, 5.59 [5.15] years; 13 842 567 [53.1%] male; 9 273 181 [35.6%] non-Hispanic white) to 32 US pediatric EDs during the 10-year study period, with 1 or more advanced imaging studies used in 1 919 283 encounters (7.4%). The proportion of ED encounters with any advanced imaging increased from 6.4% (95% CI, 6.2%-6.2%) in 2009 to 8.7% (95% CI, 8.7%-8.8%) in 2018. The proportion of ED encounters with CT decreased from 3.9% (95% CI, 3.9%-3.9%) to 2.9% (95% CI, 2.9%-3.0%) (P < .001 for trend), with ultrasonography increased from 2.5% (95% CI, 2.5%-2.6%) to 5.8% (95% CI, 5.8%-5.9%) (P < .001 for trend), and with MRI increased from 0.3% (95% CI, 0.3%-0.4%) to 0.6% (95% CI, 0.6%-0.6%) (P < .001 for trend). The largest decreases in CT rates were for concussion (-23.0%), appendectomy (-14.9%), ventricular shunt procedures (-13.3%), and headaches (-12.4%). Factors associated with increased use of nonradiating imaging modalities included ultrasonography for abdominal pain (20.3%) and appendectomy (42.5%) and MRI for ventricular shunt procedures (17.9%) (P < .001 for trend). Across the study period, EDs varied widely in the use of ultrasonography for appendectomy (median, 57.5%; interquartile range [IQR], 40.4%-69.8%) and MRI (median, 15.8%; IQR, 8.3%-35.1%) and CT (median, 69.5%; IQR, 54.5%-76.4%) for ventricular shunt procedures. Overall, ED length of stay did not change, and hospitalization and 3-day ED revisit rates decreased during the study period.

Conclusions and Relevance

This study found that use of advanced imaging increased from 2009 to 2018. Although CT use decreased, this decrease was accompanied by a greater increase in the use of ultrasonography and MRI. There appears to be substantial variation in practice and a need to standardize imaging practices.

More data, more questions: No simple answer about which children should undergo screening neuroimaging for clinically occult abusive head trauma

Abusive head trauma (AHT) is the leading cause of fatal child physical abuse. Victims may initially present with clinically occult AHT without overt signs of head trauma or with only subtle, nonspecific symptoms, which can make timely recognition of AHT challenging. Research has shown missed opportunities for early detection of AHT in the medical setting are common and can lead to repeated injury. Neuroimaging is needed to diagnose clinically occult AHT but is not without risk. Researchers have worked to understand the yield of neuroimaging in detection of clinically occult AHT and to identify risk factors, yet findings have varied widely across studies. Identifying which children undergoing physical abuse evaluations are at highest risk of clinically occult AHT is key to development of evidence-based imaging decision support tools for clinicians. Here we discuss the recent literature, identify potential reasons for variation across studies, and offer opportunities for future research.

3D pediatric cranial bone imaging using high-resolution MRI for visualizing cranial sutures: a pilot study

OBJECTIVE

There is an unmet need to perform imaging in young children and obtain CT-equivalent cranial bone images without subjecting the patients to radiation. In this study, the authors propose using a high-resolution fast low-angle shot golden-angle 3D stack-of-stars radial volumetric interpolated breath-hold examination (GA-VIBE) MRI sequence that is intrinsically robust to motion and has enhanced bone versus soft-tissue contrast.

METHODS

Patients younger than 11 years of age, who underwent clinical head CT scanning for craniosynostosis or other cranial malformations, were eligible for the study. 3D reconstructed images created from the GA-VIBE MRI sequence and the gold-standard CT scan were randomized and presented to 3 blinded reviewers. For all image sets, each reviewer noted the presence or absence of the 6 primary cranial sutures and recorded on 5-point Likert scales whether they recommended a second scan be performed.

RESULTS

Eleven patients (median age 1.8 years) underwent MRI after clinical head CT scanning was performed. Five of the 11 patients were sedated. Three clinicians reviewed the images, and there were no cases, either with CT scans or MR images, in which a reviewer agreed a repeat scan was required for diagnosis or surgical planning. The reviewers reported clear imaging of the regions of interest on 99% of the CT reviews and 96% of the MRI reviews. With CT as the standard, the sensitivity and specificity of the GA-VIBE MRI sequence to detect suture closure were 97% and 96%, respectively (n = 198 sutures read).

CONCLUSIONS

The 3D reconstructed images using the GA-VIBE sequence in comparison to the CT scans created clinically acceptable cranial images capable of detecting cranial sutures. Future directions include reducing the scan time, improving motion correction, and automating postprocessing for clinical utility.

Occult head injuries in infants evaluated for physical abuse

BACKGROUND

Abusive head injuries in infants may be occult but clinically or forensically important. Data conflict regarding yield of neuroimaging in detecting occult head injuries in infants evaluated for physical abuse, with prior studies identifying yields of 4.3-37.3 %.

OBJECTIVES

(1) To quantify yield of computed tomography or magnetic resonance imaging in identification of occult head injuries in infants with concerns for physical abuse and (2) to evaluate risk factors for occult head injuries.

PARTICIPANTS AND SETTING

We conducted a retrospective, stratified, random systematic sample of 529 infants <12 months evaluated for physical abuse at 4 urban children's hospitals in the United States from 2008-2012. Infants with signs or symptoms suggesting head injury or skull fracture on plain radiography (N = 359), and infants without neuroimaging (N = 1) were excluded.

METHODS

Sampling weights were applied to calculate proportions of infants with occult head injuries. We evaluated for associations between hypothesized risk factors (age <6 months, rib or extremity fracture, facial bruising) and occult head injury using chi-square tests.

RESULTS

Of 169 neurologically normal infants evaluated for abuse, occult head injury was identified in 6.5 % (95 % CI: 2.6, 15.8). Infants <6 months were at higher risk (9.7 %; 95 % CI: 3.6, 23.3) than infants 6-12 months (1.0 %; 95 % CI: 1.3, 20.2). Rib fracture, extremity fracture and facial bruising were not associated with occult head injury.

CONCLUSIONS

Occult head injuries were less frequent than previously reported in some studies, but were identified in 1 in 10 infants <6 months. Clinicians should have a low threshold to obtain neuroimaging in young infants with concern for abuse.

Children With Minor Blunt Head Trauma Presenting to the Emergency Department

In our state-of-the-art review, we summarize the best-available evidence for the optimal emergency department management of children with minor blunt head trauma. Minor blunt head trauma in children is a common reason for emergency department evaluation, although clinically important traumatic brain injuries (TBIs) as a result are uncommon. Cranial computed tomography (CT) scanning is the reference standard for the diagnosis of TBIs, although they should be used judiciously because of the risk of lethal malignancy from ionizing radiation exposure, with the greatest risk to the youngest children. Available TBI prediction rules can assist with CT decision-making by identifying patients at either low risk for TBI, for whom CT scans may safely be obviated, or at high risk, for whom CT scans may be indicated. For clinical prediction rules to change practice, however, they require active implementation. Observation before CT decision-making in selected patients may further reduce CT rates without missing children with clinically important TBIs. Future work is also needed to incorporate patient and family preferences into these decision-making algorithms when the course of action is not clear.

The evaluation of suspected child physical abuse

Child physical abuse is an important cause of pediatric morbidity and mortality and is associated with major physical and mental health problems that can extend into adulthood. Pediatricians are in a unique position to identify and prevent child abuse, and this clinical report provides guidance to the practitioner regarding indicators and evaluation of suspected physical abuse of children. The role of the physician may include identifying abused children with suspicious injuries who present for care, reporting suspected abuse to the child protection agency for investigation, supporting families who are affected by child abuse, coordinating with other professionals and community agencies to provide immediate and long-term treatment to victimized children, providing court testimony when necessary, providing preventive care and anticipatory guidance in the office, and advocating for policies and programs that support families and protect vulnerable children.